The present invention relates to a method of immobilizing toxic waste materials, particularly low level radioactive waste, and generating resultant useful products.
At the present time, a great deal of effort is being expended for finding economic and effective methods of disposing of hazardous waste, particularly radioactive waste, in such a manner that it does not leach into the soil or water supply. Large amounts of such low-level and high-level waste or low-level and high-level radioactive hazardous waste has been generated by both military and peaceful uses, such as electrical power generation and medical uses such as tracers. Initially, these materials were disposed of in landfills, but as long term hazards from such disposal were identified, such disposal methods were no longer permitted. Further complicating the problem, such waste became regulated without any proper approved disposal method. Consequently, much of this waste generated and still being generated is placed in storage for future disposal and known contaminated areas isolated for future cleanup. Congress enacted the Resource Conservation and Recovery Act (RCRA) mandating cleanup and disposal of these materials. The majority of such waste is "owned" by the Department of Energy and nuclear power plants and they are trying to develop approved disposal methods.
The leading method (Best Avalable Technique "BAT") at the present time is vitrification, which attempts to incorporate the radioactive wastes into sand and molten glass, with an aim to immobilizing the hazardous components upon solidification. This, despite years of effort, has not proven to be successful, particularly because of the associated problems of volatilization of hazardous components during encapsulation, accelerated leaching of hazardous components at the crack tips which form as the glassy mixture cools, and the expense associated with this method.
In addition to health and safety threats, it is estimated that it will cost an estimated $300 billion over 30 years just to clean up the radioactive and hazardous waste at the former nuclear weapons plants around the country.
There, thus, still exists a need to inexpensively immobilize such hazardous waste so that it can be disposed of without presenting any pollution problem, and which particularly adheres to the EPA leachability requirements and the Clean Water Act, so as to render the hazardous material innocuous.